In piston-type internal-combustion engines which operate with conventionally controlled cylinder valves and in which the load control is effected by a butterfly valve, controlling the air quantities for adjusting the idling run may be effected by the butterfly valve. A different method for (stabilizing) the idling run must be found, however, for piston-type internal-combustion engines having a throttle-less load control, particularly internal-combustion engines which have fully variably controllable cylinder valves, such as cylinder valves which are operated by electromagnetic drives.